Thanks fmurphy for your reply.

if I have a structure defined at the beginning in another prgm instaed of an char array name[20],can I use like this?

struct bio {
char name[20];
int age;
float salary;
}

main()
{
struct bio mydata;
--------
--------
--------

read(fd, &mydata, (size_t) ))

}
How can we use the size_t with structure?

Thanks in Advance..

Ramkrix